James w



(No Model.)

J. W. MODONOiUGH.

. TELEPHONE.

. No! 248,902., Patented 001:.4, 188;.

w%sz v v INVENTOR I ATTQRNEY,

N. PETERS. Fhnlolilhaumuher. Washi c.

UNITED STATES PATENT OFFICE.

JAMES w. McDoNoUeH, OF CHICAGO, ILLINOIS, ASSIGNOR T LOGAN o.

' MURRAY, OF NEW YORK. I

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 248,002, dated October 4, 1881.

' Application filed May 31,1881. (No model.)

To all whom it may concern Be it known that I, J AMES W. MCDONOUGH, of vthe city of Chicago, in the county of Cook,

State of Illinois, have invented a new and useful Telephone, (for which I made an application for patent April 10, 187 6 and I do hereby declare the following to be a full, clear, and exact descriptionthereof, which will enable others skilled in the art to which my invention appertains to make and use the same, reference being bad to the accompanying drawings. p

The general object of my invention, as I have set forth in my original application and in other divisions thereof filed of even date with this division, is to provide a means for transmittin g articulate sounds from one place to another through the mediumof electricity; but the part of my invention to which this present division of my said application appertains consists in a certain combination of devices for a telephonetransmitter,.specifically set forth in the claim at the end of. this schedule.

7 In other divisions of my said application of April 10, 1876, filed at an even date with this present one, I have specified and claimed other combinations or subject-matter, which, so far as this division is concerned, are not here claimed, but are specified at the end of this schedule.

In order that personsskilled in the art may understand, make, and use my present invention, I will proceed to describe the manner in which I have constructed and combined it with other parts in a telephone apparatus.

Figure 1 shows a perspective view of a telephone transmitter embodying my invention joined in circuit-with my telephone-receiver. Fig. 2 represents a sectional plan of the receiver, taken on line 00 as drawn across Fig. 1. Fig. 3 represents a vertical transverse section of the telephone-transmitter, taken on line y y and Fig.4 represents a general plan or top View of the same with the circuit-controller removed.

Like letters of reference represent like parts.

In the drawings, Arepresents the transmitting membrane or apparatus, composed of vellum or any suitable material that is sensitive to the vibrations of sound, which is stretched upon a metal hoop or band, a, permanently attached to the bed A by angle pieces T, Fig. 1.

O O are metal plates, of German silver or such like material, attached to the upper surface of the membrane A, each side of its center or point of greatest range of vibrations, and insulated from each other.

D is the circuit-controller, which consists of an arch-shaped piece of German silver or like material,loosely secured at its center upon the boltD and-bent upward at each end from the membrane A, as shown in Fig. 3, so as to form depending V-shaped legs,adapted to rest upon the respective plates 0 O, and to make contact between their granular surfaces and the granular surfaces of the plates.

In the telephone-transmitting instruments of Philip Reis and others, as constructed prior to my invention, no positive provision is made for limiting or confining the movements of the controller with relation to the contact-plate in connection with the diaphragm.

The device which I employ in combination 7 with the controller obviates the difficulties and imperfections existing in the former inst-ruments,increases the capacity of the apparatus, and supplies a means whereby the action of the controller may be governed and adjusted, so that the best operation is attained.

The adjustable controlling or limiting device for the circuit-controller consists of a nut, E, upon a bolt, D, which is attached to the membrane A centrally between the plates, and is insulated from them and passes through an opening in the circuit-controller.

By moving the nut up and down upon the bolt the extent of movement of the controller with reference to the contact-plates may be adjusted until the best results are obtained.

able material that is sensitive to the vibrations of sound, and is stretched upon a metal hoop or band, a, secured to the side frame, G, of 5 wood or such like insulating material, of the receiving or sounding apparatus, as shown in Fig. 1.

G is the magnet, of a continuous piece of iron surrounded by a helix of insulated wire, [on

and connected to the instrument immediately in front of the membrane F, and at a point near its center.

H is a thin metal armature-plate, permanently attached to and supported by the membrane F, between it and the magnet, as shown in Fig. 1, so that the membrane receives the exact and entire motion of its whole area.

B is a sound-recess in the frame or holder of the receiver, inclosed on its sides or circumfer once by the wood of the frame G, and on the end near the magnet by the membrane, so that the sounds emitted by the armature and membrane may be confined and directed to the ear of the listener, while all exterior sounds are excluded.

To each of the plates 0 O is connected a wire, J, one of which is connected with the battery K and the other with the ground-wire L.

To each of the poles of the magnet is connected a wire, M, one of which is connected with the battery K and the other to the groundwire, as shown in Fig. 1, by means of connecting-posts N N, mounted or fixed in the wooden frame at the same end with the magnet, and insulated therefrom and from one another by the material of the holder.

The operation of my telephone apparatus is as follows: The transmitting-membrane being at rest, the circuit controller rests upon the plates and completes the circuit of the electric battery through the helix of the receiving apparatus. The said membrane being sensitive to sound-vibrations produced in its vicinity is made to vibrate thereby, and the circuit-controllerD, restingupon the plates, is caused also to vibrate, the extent or limit of its movements or vibrations with reference to the contactplates being determined by the nut, which is suitablyadjustediorthatpurpose. Pulsations ofthe electric currentfiowing through the wires and thehelix of thereceiver are thus produced, and the membrane of the recei veris thus caused to vibrate in response to the action of the sound-waves upon the transmitter.

Having now fully described my invention of a telephone apparatus, as shown and set forth in the drawings and specification filed in the Patent Ofiice April 10, 1876, I wish it to be understood that in this present division of my application Imalte no claim to the combination of my diaphragm-receiver with my diaphragm-transmitter, nor do I in this present division make any broad claim to my receiver, nor to the other particular inventions covered by other divisions of my application. In this presentdivision I do not therefore claim the subject-matter claimed in the other divisions of my original application, filed of even date with this present division, which claims, as contained in the several divisions now on file, and in the divisions patented August 9, 1881, N 0245,5341, and September 6, 1881, No. 246,800, are as follows:

First, a telephone-receiver consisting of the combination, in an electric circuit, of a magnet and a diaphragm supported and arranged in close proximity thereto, whereby sounds thrown upon the line may be reproduced accurately as to pitch and quality, substantially in the manner hereinbefore set forth.

Second, the combination, substantially as herein before set forth, of a transmitting-membrane composed of vellum or any suitable material that is sensitive to the vibrations of sound, and a piece or pieces of conducting material connected with the same, and receiving from it vibrations less in extent than its extreme range of vibration with a circuit-controller, which, when at rest, has points of contact with said conducting piece or pieces, makin g part of an electric circuit through them and the battery, and which receives from the membrane, when in motion, said reduced vibrations in accord with the waves of air producing sound, and thereby causes impulses in the electric current through the said conducting piece or pieces, all constructed and operating substantially in the manner described.

Third, the combination, substantially as hereinbet'ore set forth, of a magnet, a helix, and a receiving-membrane, a portion of. the face of which presents a material attached to and supported wholly by the membrane, capable of being attracted by the magnet, and in close proximity thereto, with connectingwires, a voltaic battery, and a transmittingmembrane, conducting-pieces connected thereto and to the circuit-wires, a circuit-controller resting upon said pieces and entirely supported thereby, and arranged to vibrate in connection with the membrane, and a regulatingnut to limit the movement of the controller with relation to said contact-pieces, all combined to operate in the manner set forth, so

that the said controller, when at rest, com

pletes the circuit of the battery, and when in motion by means of sound-waves causes electrical pulsations in the connecting-wires and helix around the magnet, and vibrations of the membrane of the receiver.

Fourth, the combination, substantially as hereinbefore set forth, for a telephone receiving apparatus, of a helix and magnet, and connecting-posts to which the wires of the helix are joined, mounted in one end of a frame or holder, of wood or such like insulating material, a membrane mounted on the opposite end of said frame or holder, a portion of the face of which membrane presents a material attached to and supported wholly thereby, capable of being attracted by the magnet, and in close proximity thereto, so that the said membrane shall be caused to vibrate by the action of pulsations in an electric current in a helix around the magnet, with a sound-recess at the opposite side of the membrane from the magnet, to confine the sounds received therein and exclude exterior sounds from the ear of the listener, and adapted at thesame time to allow the ear of the listener to be placed in close proximity to the membrane, all con- IIO 24s,o02 r 3 structed and arranged to operate substantially in the manner described.

Fifth, broadly, the art oftransmittin g articulate speechby electricity.

Sixth, broadly, a variable resistance-contact transmitter for electro-speaking telephones.

Seventh,broadly,amagneto-receiver for electro-speaking telephones.

What I do claim in this division as part of my whole invention, and desire to secure by Letters Patent, is-

The combination, substantially as hereinbe- .fore set forth, of a transmitting-membrane composed of vellum or any suitable material that is sensitive to the vibrations of sound, and two pieces of conducting material attached to and receiving motion from the same, and in- 

